1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to digital audio broadcasting (DAB), and more particularly, to providing and receiving a video service in DAB.
2. Description of the Related Art
Analog audio broadcasting has drawbacks in that the quality of a signal input to an analog audio receiver significantly deteriorates when the analog audio receiver is moving; power efficiency is poor since strong transmission power is required to hide noise; and spectrum efficiency is poor due to the use of different frequencies in neighboring regions to eliminate channel interference. To address these problems, research into digital audio broadcasting (DAB) as a substitute for existing analog radio broadcasting, such as amplitude modulation (AM) and frequency modulation (FM) radio broadcasting, has been conducted. The European Telecommunication Standardization Institute (ETSI) has established the ETSI EN 300 401 standard for DAB.
ETSI EN 300 401, also called EUREKA-147, describes the provision of audio service and various additional services having compact disc (CD)-level quality at a bandwidth of about 2 MHz using a high-quality audio compression technique according to Moving Picture Experts Group (MPEG)-1 audio layer II. A plurality of audio data services are transmitted using Unequal Error Protection (UEP) and a plurality of data services are transmitted using Equal Error Protection (EEP) so as to optimize rates of data transmission at limited bandwidth and in a channel environment.
Through DAB, high-quality multi-channel audio and various types of additional data can be transmitted. Examples of additional data include still images, moving images, and graphics data. By transmitting the additional data, it is possible to provide multimedia services such as travel and traffic information, a program linkage information service that provides news images combined with headline characters or weather forecast and traffic information combined with electronic maps, a program independent information service that provides web site broadcasting or a Global Positioning System (GPS) for DAB, and a moving image service.
Among those services, an audio service, a packet mode data service, and a stream mode data service are provided according to the DAB standard (ETSI EN 300 401), but a video service using the stream mode data service is not prescribed in the DAB standard. As a result, for transmission/reception of video data, the DAB standard needs to be amended. This is because, in this case, although a separate standard determining a transmission method of a broadcasting station and a reception method of a receiver should be agreed between the broadcasting station and the receiver, a receiver that does not adhere to the standard cannot be provided with the video service through a DAB stream mode.
When the video service is provided using the stream mode data service that is a main service channel, encoding parameters related to the video service and information regarding a method used to packetize video data are generally included in a video service stream. Thus, for the video service, the encoding parameters used to encode data related to the video service and the method used to packetize the video data should be capable of determination by decoding the main service channel of DAB.